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<div class="title">Systick Timer (SYSTICK)</div>  </div>
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<p>Initialize and start the SysTick timer.  
<a href="#details">More...</a></p>
<table class="memberdecls">
<tr><td colspan="2"><h2><a name="func-members"></a>
Functions</h2></td></tr>
<tr><td class="memItemLeft" align="right" valign="top">uint32_t&#160;</td><td class="memItemRight" valign="bottom"><a class="el" href="group___sys_tick__gr.html#gabe47de40e9b0ad465b752297a9d9f427">SysTick_Config</a> (uint32_t ticks)</td></tr>
<tr><td class="mdescLeft">&#160;</td><td class="mdescRight">System Tick Timer Configuration.  <a href="#gabe47de40e9b0ad465b752297a9d9f427"></a><br/></td></tr>
</table>
<hr/><a name="details" id="details"></a><h2>Description</h2>
<p>The System Tick Time (SysTick) generates interrupt requests on a regular basis. This allows an OS to carry out context switching to support multiple tasking. For applications that do not require an OS, the SysTick can be used for time keeping, time measurement, or as an interrupt source for tasks that need to be executed regularly.</p>
<h2><a class="anchor" id="SysTick_code_ex_sec"></a>
Code Example</h2>
<p>The code below shows the usage of the function <a class="el" href="group___sys_tick__gr.html#gabe47de40e9b0ad465b752297a9d9f427" title="System Tick Timer Configuration.">SysTick_Config()</a> with an LPC1700.</p>
<div class="fragment"><pre class="fragment"><span class="preprocessor">#include &quot;LPC17xx.h&quot;</span>

uint32_t msTicks = 0;                                       <span class="comment">/* Variable to store millisecond ticks */</span>

                                            
<span class="keywordtype">void</span> SysTick_Handler(<span class="keywordtype">void</span>)  {                               <span class="comment">/* SysTick interrupt Handler.</span>
<span class="comment">  msTicks++;                                                   See startup file startup_LPC17xx.s for SysTick vector */</span> 
}


<span class="keywordtype">int</span> main (<span class="keywordtype">void</span>)  {
  uint32_t returnCode;

  returnCode = <a class="code" href="group___sys_tick__gr.html#gabe47de40e9b0ad465b752297a9d9f427" title="System Tick Timer Configuration.">SysTick_Config</a>(<a class="code" href="group__system__init__gr.html#gaa3cd3e43291e81e795d642b79b6088e6" title="Variable to hold the system core clock value.">SystemCoreClock</a> / 1000);      <span class="comment">/* Configure SysTick to generate an interrupt every millisecond */</span>

  <span class="keywordflow">if</span> (returnCode != 0)  {                                   <span class="comment">/* Check return code for errors */</span>
    <span class="comment">// Error Handling </span>
  }

  <span class="keywordflow">while</span>(1);
}
</pre></div> <hr/><h2>Function Documentation</h2>
<a class="anchor" id="gabe47de40e9b0ad465b752297a9d9f427"></a><!-- doxytag: member="Ref_Systick.txt::SysTick_Config" ref="gabe47de40e9b0ad465b752297a9d9f427" args="(uint32_t ticks)" -->
<div class="memitem">
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          <td class="memname">uint32_t SysTick_Config </td>
          <td>(</td>
          <td class="paramtype">uint32_t&#160;</td>
          <td class="paramname"><em>ticks</em></td><td>)</td>
          <td></td>
        </tr>
      </table>
</div>
<div class="memdoc">
<p>Initialises and starts the System Tick Timer and its interrupt. After this call, the SysTick timer creates interrupts with the specified time interval. Counter is in free running mode to generate periodical interrupts.</p>
<dl><dt><b>Parameters:</b></dt><dd>
  <table class="params">
    <tr><td class="paramdir">[in]</td><td class="paramname">ticks</td><td>Number of ticks between two interrupts</td></tr>
  </table>
  </dd>
</dl>
<dl class="return"><dt><b>Returns:</b></dt><dd>0 - success </dd>
<dd>
1 - failure</dd></dl>
<dl class="note"><dt><b>Note:</b></dt><dd>When <b>#define __Vendor_SysTickConfig</b> is set to 1, the standard function <b>SysTick_Config</b> is excluded. In this case, the file <b><em>device</em>.h</b> must contain a vendor specific implementation of this function. </dd></dl>

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